1. Technical Field
This invention pertains to a roller mechanism to be attached to an object, such as a table or other piece of furniture, to enable that object to be easily moved across a surface, such as a floor. The roller mechanism may be rotated to permit the object to rest on the surface in a stationery position.
The rotatable roller facilitates the movement of heavy machinery, equipment, or furniture, which may be rolled across a floor using the method of this invention. As is frequently desired or necessary for safety, such machinery and furniture may be left in a stationery position, without a complex disabling or removal of the roller mechanism.
2. Background Art
Various retractable mechanisms are known in the prior art which may be attached to furniture or equipment to facilitate the movement of that object. For example, U.S. Pat. No. 2,490,953 to Eriksen and 112,740 to Ryder describe caster mechanisms which may be used to allow various types of furniture to be rolled across a floor surface. In each case, the caster extends from the furniture on a rod, which rod may be moved to an extension position or a retracted position, and locked into position by engaging a screw or lever. The furniture to which such a caster is attached must have significant empty space between the body of the furniture and the floor to permit storage of the caster mechanism in its retracted position.
Similarly, the stove leg described in U.S. Pat. No. 251,949 to Risdon involves a caster on a rod. The mechanism may be contained within a leg as large and tall as the stove leg contemplated by the patent, but could not be utilized to move equipment which lies flat on a floor surface, without legs.
Less empty space under the furniture is required to store the retracted furniture caster described in U.S. Pat. No. 1,145,096 to Thomes. Nevertheless, movement of the caster through an arched slot into a locked position does require space which makes it impossible for the furniture to lie flush with the surface. Furthermore, this mechanism requires manually or foot applied pressure to move the caster to its retracted position.
Similar axle mounted casters are described in U.S. Pat. No. 1,019,302 to Butcher, 1,136,915 to Adams, and 4,008,507 to Smith. In each of these designs an axle bearing a caster is movable between two slots, one of which results in retraction of the caster into it's housing, and one of which results in extension of the caster for moving the object. The object to which the caster is attached must be both lifted and moved laterally to re-position the caster.
A retractable caster described in U.S. Pat. No. 2,779,049 to Hoddevik swings between two positions, by tilting the object to which it is attached. In one of these positions, the object may be moved across a surface by rolling the caster. The object will be stationery in the second position, as the caster lies at an angle to its vertical position, between the surface and the underside of the object. The Hoddevik design requires the use of a caster, as opposed to a roller which has a smaller diameter than a caster, a longer width for supporting heavier objects, and motion restricted to forwards and backwards, as opposed to multiple angled directions. The caster may be moved from its retracted position into the position in which it may be rolled across the surface by lifting the side of the object which is opposite the caster, to a height greater than the caster's distance from the surface. This may require a large force for heavy objects. Furthermore, this lifting action may result in shifting a second caster, at a different place on the object, to its retracted position.
U.S. Pat. No. 2,814,498 to Hull describes a retractable carriage mounting in which a caster may exist in one of two positions. A lock mechanism must be manually disengaged prior to moving the caster to its retracted position.
Each of the retractable caster or roller designs known in the prior art is useful for its intended purpose. However, these designs share certain limitations. The bulkiness inherent in these mechanisms, particularly when the caster is retracted, make it impossible to use most of these devices for equipment which lies flush on a floor surface. Furthermore, many of these designs require manipulation of the mechanism by hand or by foot to alternate between the extended and retracted positions. Alternatively, some of these designs require the object to be significantly lifted prior to engaging the caster mechanism, which may be difficult if the object is heavy machinery. A device is needed which may be attached to furniture and equipment either with or without legs, and which is securely positioned either to move the object or maintain a stationery location, without complex adjustments or manipulation.